initial commit

examples/gno.land/r/matijamarjanovic/tokenhub/gno.mod

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+module gno.land/r/matijamarjanovic/tokenhub

examples/gno.land/r/matijamarjanovic/tokenhub/test.gno

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+package tokenhub
+
+import (
+	"std"
+
+	"gno.land/p/demo/grc/grc20"
+)
+
+var (
+	tokenA *grc20.Token
+	tokenB *grc20.Token
+	tokenC *grc20.Token
+	tokenD *grc20.Token
+	tokenE *grc20.Token
+)
+
+func init() {
+	tokenA = grc20.NewToken("Token A", "TKNA", 6)
+	tokenB = grc20.NewToken("Token B", "TKNB", 6)
+	tokenC = grc20.NewToken("Token C", "TKNC", 6)
+	tokenD = grc20.NewToken("Token D", "TKND", 6)
+	tokenE = grc20.NewToken("Token E", "TKNE", 6)
+
+	Send5OfEach("g1ej0qca5ptsw9kfr64ey8jvfy9eacga6mpj2z0y")
+	RegisterToken(tokenA)
+	RegisterToken(tokenB)
+	RegisterToken(tokenC)
+	RegisterToken(tokenD)
+	RegisterToken(tokenE)
+}
+
+func Send5OfEach(to std.Address) error {
+	if !to.IsValid() {
+		return grc20.ErrInvalidAddress
+	}
+
+	if err := adminA.Mint(to, 5); err != nil {
+		return err
+	}
+	if err := adminB.Mint(to, 5); err != nil {
+		return err
+	}
+	if err := adminC.Mint(to, 5); err != nil {
+		return err
+	}
+	if err := adminD.Mint(to, 5); err != nil {
+		return err
+	}
+	if err := adminE.Mint(to, 5); err != nil {
+		return err
+	}
+
+	return nil
+}

examples/gno.land/r/matijamarjanovic/tokenhub/tokenhub.gno

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+package tokenhub
+
+import (
+    "std"
+    "errors"
+	"strings"
+    "gno.land/p/demo/avl"
+    "gno.land/p/demo/grc/grc20"
+	"gno.land/p/moul/md"
+	"gno.land/p/demo/ufmt"
+)
+
+var (
+    registeredTokens = avl.NewTree() // symbol -> *grc20.Token
+
+    ErrTokenAlreadyRegistered = errors.New("token already registered")
+    ErrTokenNotFound = errors.New("token not found")
+)
+
+func RegisterToken(token *grc20.Token) error {
+    symbol := token.GetSymbol()
+
+    if registeredTokens.Has(symbol) {
+        return ErrTokenAlreadyRegistered
+    }
+
+    registeredTokens.Set(symbol, token)
+    return nil
+}
+
+func getBalances(addr std.Address) string {
+    balances := avl.NewTree()
+    var sb strings.Builder
+
+    registeredTokens.Iterate("", "", func(key string, value interface{}) bool {
+        token := value.(*grc20.Token)
+        balance := token.BalanceOf(addr)
+        balances.Set(key, balance)
+        return false
+    })
+
+    sb.WriteString("Balances: ")
+    balances.Iterate("", "", func(key string, value interface{}) bool {
+        balance := value.(uint64)
+        sb.WriteString(ufmt.Sprintf("%s: %d ", key, balance))
+        return false
+    })
+
+    return sb.String()
+}
+
+func GetMyBalances() string {
+    return getBalances(std.GetOrigCaller())
+}
+
+func Render(path string) string {
+    var sb strings.Builder
+
+    sb.WriteString(md.H1("TokenHub"))
+    sb.WriteString(md.Paragraph("A central registry for GRC20 tokens on gno.land"))
+
+    sb.WriteString(md.H2("Registered Tokens"))
+
+	var tokenItems []string
+    registeredTokens.Iterate("", "", func(key string, value interface{}) bool {
+        token := value.(*grc20.Token)
+        tokenItems = append(tokenItems, ufmt.Sprintf("%s (%s) - %d decimals", 
+            token.GetName(),
+            token.GetSymbol(), 
+            token.GetDecimals()))
+        return false
+    })
+
+    if len(tokenItems) > 0 {
+        sb.WriteString(md.BulletList(tokenItems))
+    } else {
+        sb.WriteString(md.Italic("No tokens registered yet"))
+        sb.WriteString("\n")
+    }
+
+    return sb.String()
+}
+